1. Field of the Invention
The present invention relates to an image reading apparatus having a plurality of sheet feed trays on each of which originals are placed, and relates to a control method of the image reading apparatus.
2. Description of the Related Art
Conventionally, an image reading apparatus having sheet feed trays on which originals are placed has been known (see, e.g., Japanese Patent Publication No. 3639614). An example image reading apparatus of this type is shown in FIG. 6 that has a substantially U-shaped main conveying path 20 and a confluent conveying path 21 merging with the main conveying path 20 at an intermediate portion of the main conveying path 20.
A sheet feed tray 15 is disposed at an upstream end of the main conveying path 20, and a sheet feed tray 16 is disposed at an upstream end of the confluent conveying path 21. On the downstream side of the position where the confluent conveying path 21 merges with the main conveying path 20, a pair of reading sensors 200a, 200b are disposed on a lower side of and on an upper side of the conveying path.
Originals D1 placed on the sheet feed tray 15 are picked up by a pickup roller 2 and separated and fed one by one by a feed roller 3 and a retard roller 4 toward the main conveying path 20. Each original D1 fed to the main conveying path 20 makes a U-turn and is then conveyed by a conveying roller pair 6 to the downstream side of the main conveying path 20, and images of both sides of the original D1 are read by the pair of reading sensors 200a, 200b. Subsequently, the original D1 is discharged by a sheet discharge roller pair 7 to a sheet discharge tray 17.
Originals D2 on the sheet feed tray 16 are separated and fed one by one by a feed roller 5 and a retard roller 52 to the main conveying path 20 via the confluent conveying path 21. Each original D2 fed to the main conveying path 20 is conveyed by the sheet conveying roller pair 6 to the downstream side of the main conveying path 20, and images of both sides of the original D2 are read by the reading sensors 200a, 200b. Then, the original D2 is discharged to the sheet discharge tray 17 by the sheet discharge roller pair 7.
Irrespective of whether an original is picked up from the sheet feed tray 15 or from the sheet feed tray 16, image data read by the lower side reading sensor 200a is handled as front side image data of the original, and image data read by the upper side reading sensor 200b is handled as back side image data of the original.
Specifically, in the case of reading images of both sides of each original, an image of a surface, upwardly directed on the sheet feed tray 15, of an original D1 picked up from the sheet feed tray 15 is read as an image of front surface of the original D1 by the lower side reading sensor 200a, and an image of a surface, downwardly directed on the sheet feed tray 16, of an original D2 picked up from the sheet feed tray 16 is read as an image of front surface of the original D2 by the lower side reading sensor 200a. Also in the case of reading an image of one side of each original, which of original surfaces (i.e., the original surface upwardly directed on each sheet feed tray or the original surface downwardly directed thereon) is read differs between the sheet feed trays for the same reason.
Accordingly, at the time of double-sided reading with the image reading apparatus shown in FIG. 6, the user placing originals on one or both of the sheet feed trays 15, 16 must confirm, for each sheet feed tray, whether the original surface upwardly directed on the sheet feed tray will be read as front surface or as back surface. Similarly, at the time of single-sided reading, the user placing originals on one or both of the sheet feed trays 15, 16 must confirm, for each sheet feed tray, which of original surfaces (i.e., the surface upwardly directed on each sheet feed tray or the surface downwardly directed thereon) will be read. The above situation lowers the user-friendliness.
As described above, the user-friendliness of an image reading apparatus having sheet feed trays is lowered in a case where an image of the original surface upwardly directed on one sheet feed tray is read as an image of front surface and an image of the original surface upwardly directed on another sheet feed tray is read as an image of back surface. To attempt to obviate this, the image reading apparatus may have a changeover function which, at the time of double-sided reading, enables handling of original's front side image data as back side image data and handling of original's back side image data as front side image data. Even in that case, an operation to select the sheet feed tray to which the changeover function is to be applied must be made via an external apparatus (e.g., PC) connected to the image reading apparatus or an operation unit of the image reading apparatus, and then an operation to enable the changeover function must be done. In this way, the user must first confirm the correct orientation (either front facing or back facing) in placing originals on each sheet feed tray, secondly select the sheet feed tray to which the changeover function is to be applied, and thirdly perform the operation to enable the changeover function. Thus, user-friendliness is still missing.
At single-sided reading of, e.g., originals printed on one surfaces thereof, the other original surfaces printed with no images, letters, etc. are wastefully read, if the originals are placed in a wrong orientation. In that case, the originals must again be placed directing the original surfaces printed with images, etc. in the correct direction and the reading operation must be performed again.